Navy SBIR leads to Resilient, rechargeable batteries Systems Courtesy Mission Photos powering autonomous undersea applications

n March 8, 2014, Malaysia Airlines Flight underwater sensor sweeps, aiding in the search. 370 disappeared over the Andaman Sea. After The Bluefin-21 AUV was developed by Bluefin- Ro an erratic flight path, it slipped off the radar botics—a small business founded in 1997 by a group of Oand under the waves, carrying 239 passengers and crew engineers from Institute of Technolo- members. The disappearance triggered one of largest, gy’s AUV lab. In February 2016, Bluefin Robotics was most extensive, and expensive multinational aviation acquired by General Dynamics Mission Systems, a search efforts in history. business unit of General Dynamics. Since the acquisi- A few weeks later, Phoenix International, a marine tion, General Dynamics has continued to invest in, and service contractor that provides worldwide manned advance, the Bluefin Robotics AUV products and relat- and unmanned underwater services, deployed a Blue- ed subsea power solutions. They are now fielded world- fin-21 autonomous underwater vehicle (AUV)—pow- wide, across both defense and commercial industries. ered by Bluefin’s 1.5kWh subsea battery—to conduct Regarding the Malaysian Air search, Chris Moore, Director of Commercial Operations, Phoenix tems business unit within General Dynamics International, said, “We had a lot of great sup- Mission Systems. port from Bluefin Robotics, and we successfully The 30-pound battery can not only be placed dove 15 times down to 5,000-plus meters, do- directly into the water, the battery electronics ing side-scan sonar surveys looking for a debris include built-in protection, monitoring, power field from the airplane crash. On one of our dives, we control, and battery conditioning. Its functional design achieved 27 hours of endurance off one of the Bluefin allows a user to simply replace a discharged battery with battery banks.” The endurance and depth both earned a charged one, enabling battery “swappability” and the world records for the Bluefin-21 AUV, which was pow- rapid turnaround of submersible equipment. ered by technology developed with the help of a Navy “You can change out the equipment very fast. Instead SBIR award. of having to open up a Certainly, under- pressure vessel, which sea search and rescue Mara said, “This SBIR takes a lot of time, you is a vital activity. But just get the AUV out the applications for the funding, as well as internal of the water, swap out Bluefin battery to power the batteries, and it is AUVs, or autonomous investment, helped us ready to re-use—all robots for underwater develop and test our new in half an hour,” said applications, extend be- Mara. yond search and rescue. battery capability down to Finally, the Blue- The Bluefin-21 is a fin 1.5-kWh subsea torpedo-shaped AUV 6,000 meters.” battery has a fully au- that can be used to con- tomated charging sys- duct both military and tem. Full battery re- civilian oceanic operations. Within the Bluefin-21 (and charge can be accomplished in six hours or less. And it other untethered robots) the Bluefin 1.5kWh subsea bat- can operate for up to 16 consecutive hours. tery is the operational foundation for use in deep water, “Power is the driving technology behind all auton- keeping sailors out of harm’s way. The AUV can be used omous robots. Our original goal was to develop a bat- for mine countermeasures, anti-submarine warfare, and tery to withstand pressure at underwater depths. This mapping of the sea floor. It also has applications in oil pressure-tolerant battery technology allows our AUVS and gas exploration, archaeological investigations, and to operate efficiently at deep depths for long durations,” for assessing infrastructure safety. Mara said. Bluefin Robotics’ subsea batteries leverage a rig- Creating a reliable underwater electric power source orously tested, fully submersible, modular design that is a challenging engineering task. With a Small Business eliminates a need for the battery to be packaged in a Innovation Research (SBIR) contract from the Navy’s heavy, sealed vessel. The rechargeable lithium-polymer Office of Naval Research in 2001, Bluefin Robotics was cells provide high energy-density and the modularity of able to achieve this feat, and emerge as a world leader in the batteries enable rapid battery swapping and speedy AUV products designed for defense, commercial, and redeployment of subsea devices or AUVs. scientific applications. “Instead of a heavy vessel that can withstand pres- Mara said, “This SBIR funding, as well as internal sure, the unique battery design saves on weight and investment, helped us develop and test our new battery space, and that increases the energy density,” said Adam capability down to 6,000 meters. That spun off into a Mara, Director of Power Systems for the Bluefin Ro- new power line that is now available to everyone. If botics product line of the Maritime and Strategic Sys- Bluefin Robotics didn’t have the SBIR, we would not Working in Boston harbor, a specialist installs a Bluefin battery into an autonomous underwater vehicle.

have been able to go to deep depths.” temperature and depth sensors, and navigation, teleme- Its UN-certified, stainless-steel shipping container try, and propulsion systems. allows AUV deliveries by ground, sea, or air, making The Bluefin battery is now a critical part of the it highly desirable for subsea emergency-response op- General Dynamics Mission Systems product family of erations, both in military and civilian theaters. “One of AUVs. These batteries have also been used to power re- the most important features concerning developing a motely operated vehicles (ROVs), profilers, buoys, and battery that is not housed in a vessel,” Mara said, “is the submersible systems. ability to respond rapidly. Our batteries can be shipped Mara added, “The AUV industry is expanding rap- anywhere, ready for use.” idly. Demand for a reliable power system is increasing. The Bluefin battery can power multiple types of The number of sensors that people use, and the number payloads, including geophysical payloads that collect of applications for subsea power, are expanding. This bathymetry data and backscatter data; high unique power solution gives users surface resolution cameras; and mineral survey access to the deepest depths of our oceans payloads. The battery also powers electric in order to carry out thousands of different field sensors, magnetometers, conductivity kinds of activities.”

Bluefin Robotics Corp. (General Dynamics) Modernization Priority: Autonomy Cambridge, MA (Fairfax, VA) • SBIR contract: N00014-01-C-0205 • Agency: Navy • Topic: N99-215, Pressure-Tolerant Batteries for Autonomous Undersea Applications